Dyeing cellulose derivatives



DYE'ING CELLULOSE DERIVATIVES Filed March 19, 1941 C. -M-CROFT w. HHINDLE.

INVENTORS MM ATTORNEYS 7 dyelngs may be meanne s, 1944 t UNITED STATE PATENT OFFICE prams. CELLULOSE DERIVATIVES Cyril M. Croft aim Wal land, Md, assignors to m n. Hindle, Cumber- Oelanese Corporation of America, a corporation of Delaware Application March 19, 1

' '14 Claims. (c1. 8- 59) Thisinvention relates to the dyeing of organic derivative of cellulose textile materials and relates more particudarly to the dyeing of organic derivative of cellulose textile materials by mechanical impregnation methods.

An object of our invention is to increase the speed of dyeing of organic derivative of cellulose textile materials.

Another object of our invention is to obtain more uniform dyeings of organic derivative 1 of cellulose textile materials and to obtain said dye ings more economicalhr.

Other objects of our from the following detailed description and the accompanying drawing,

The drawing shows diagrammatically'a side elevation of a padding device, one, form of aPPfl invention will appear ratus by which our invention may be practiced. In the coloration of textile materials by means j ,of dye baths-it is highly desirable that the depth of shade desired in the textile material be reached with as short an immersion time and as little handling of the material as possible." When dyeing organic derivative of cellulosetextile materials, however, it has been found that these materials are dyed more slowly th'an other textile" I materials since they are less absorbent and the dye liquor in the'dye bath does not penetrate them as rapidly or as completely as other textile material. Many dyestuifs when applied to organic derivative of cellulose material from aqueous baths yield-dyeings which are far from, satisfactory and consequently long periods, of immersion and manipulation are usually required in order to dye" the textile materials in suiliciently' deep, non-fugitive shades.

We have now discovered that organic derivative of cellulose textile materials may. be dyed rapidly in deep, uniform, level shades with dye-' stufls normally having little or no afllnity for or- 941, Serial No.'384,058

ployed and which exertat leasta swelling or sot 'tening action on the organicderivatives. of cellulose. Whilewe prefer in the. dyeliquor, other alcohols such as methyl alcohol, propyl alcohol, isopropyl alcohol, n-

butyl alcohol, secondary butyl butyl alcohol, 'n-amylalcohol, alcohol andtertiary amyl alcohol, or mixtures ofthese alcohols may be used. The amount of the alcohol used in the dye liquor will vary depending upon the alcohol or-alcohols used, but

alcohol, tertiary should'comprise at least 70%, by weight, of the dye bath. Where ethyl alcohol being used the dye liquor should preferably contain from about '15 to 80% by weight of the alcohol. I

Various dyestufis may be employed, These dyestuffs may be acid dyes which are used for the dyeing of wool and normally show little or no affinity for organic derivatives of cellulose, or they may be thosedyes which are relatively insoluble in water and which are applied to organic derivative of cellulose materials in the form of aqueous dispersions after being specially solubilized. when these dyestuffs are applied to organic derivative of cellulose textile materials by mechanical impregnation methods in alcoholic solutions in accordance with our process, the resulting dyeings are or uniform depth'andbrilliance and may be obtained with relatively short immersion times. The amount ofthe dyestufl dissolved in the dye liquor will vary depending upon' the final shade desired in the material which is being dyed and may be from as low as 0.01% up to 4.0%, based on the weight of the material to be dyed.

The dye liquor may be derivative of cellulose textile materials .by padganic derivatives of cellulose and relatively water insoluble dyestuffs which are usually applied in dispersed or solubilized form, if said dyestuffs are dissolved in an organicliquid' medium comprising a at .least 70% by weight of a lower aliphatic alding, spraying or by'other convenient method of v mechanical impregnation. Thus, as acontinuous process, a fabric may be unwound from aroll, passed through a solution of the dyestufi, then between nipping rolls of a padding mangle which are adjusted to permit thedesired amount .of dye liquor to be retained in the fabric, and the fabric then subjected to rapid drying. The period of immersionof the fabric in the dye liquor is relatively short and may be from 1% to 10 seconds. If desired, the fabric may be processed through thepadding mangle at speeds ranging upto45 yards per minute,

, Not only is our process applicable to the dyeing of fabrics, but especially desirable results are ob-- tained when organic derivative of cellulose staple fiber in the form of a top is dyed in this way. Not

only may more uniform dyeings be obtained but to employ ethyl alcohol secondary amyl applied to the organic with nating the necessity for adding additional color while the fabric or top is dyeing. The level of liquid in the dye bath is maintained by the addition thereto from time to time of dye liquor of the same composition as'that initially employed to replace that portion of the dye liquor carried out by the fabric. Consequently, there is no need to drop incompletely exhausted dye baths when the final shade is obtained as in conventional methods of dyeing, and this source of loss or waste of color is eliminated. When dyeing staple fibers in the form of a top, a large number of ends may harm through the dye bath at the same time and padded by a single pad, thus greatly increasing the rate of production of dyed staple without additional equipment. The time of im-v mersion of the top in the dye liquor prior to padding may be from 1 seconds to 2 minutes. After padding, the dyed top is subjected to rapid drying.

- e dyed textile materials in the form of fabrics or tops may be dried by pusingsaid materials through a. chamber through which there is circulated air heated to temperatures-up to about 95 C. for quite rapid drying and heated to say 70 C. to 90 C. for less rapid drying.

Where the particular solvent mixture used exerts a marked swelling action on the organic derivatives of cellulose it is advantageous that'the materials be dried rapidly. While drying by means of heated air is preferable, heated drums or cans may also be used.

The organicderivative of cellulose fabrics, tops, yarns or other textile materials which may be dyed in accordance with our process may be cellulose esters or cellulose ethers. Examplesof cellulose esters are cellulose acetate, cellulosepropionate, cellulose butyrate, and mixed esters such as cellulose acetate-proplonate and cellulose acetate butyrate, while examples of cellulose ethers are-ethyl cellulose and benzyl .cellulose.

ingorganic derivatives of cellulose and yarns rality of rolls 4, 5 and 6, which are suitably driven-for continuous rotation. While a three roll pad mangle is shown in the drawing, a two roll pad mangle may be employed if desired. The nip or distance between said rolls may be adjusted as desired in accordance with the type of material being processed and the quantity of liquor which is to be permitted to remain thereon. The fabric 1 which is being dyed, may be drawn from a roll 8 wound about a suitable core 9 which is mounted so as to be freely'rotatable. The fabric is passed over guide rolls l and H and is. then passed-into the dye'liquor under roller 3. The fabric carrying the dye liquor is then passed over an expander bar l2 and into the nip of rolls 4 and which is so adjusted as to permit the fabric 1 to retain the desired amount .of dye liquor thereon. The dye liquor expressed from the fabric is caught by means of a suitable trough (not shown) placed below the rolls of the padding mangle. .After'passing through the'nip of rolls 4 and 5, the fabric 1 is passed over another expander-bar l3 and through the dip of rolls 6 and 6, after which' it passes over guide rollers I4 and I5 and enters a tall heated chamber I where the dye solvent is removed by heated air circulated by means of a hot blower ll. When a two roll pad mangle is used, only a single expander bar need be employed. The use of expander bars in connection with this pad dyeing device both before and after the wet fabric enters the nip of the padding mangle overcomes any difficulties experienced, in processing the fabric due, to creasing or to shrinkage in thedye bath and comprises a novel advance in the art. It will of course be understood that the method of immersion of the fabric in the dye liquor may be varied. In lieu of merely passing the fabric under a roll, the fabric may be-passed through the nip of a pair of rolls submerged in the dye bath or else the fabric may first be dipped and then nipped between submerged rolls. Likewise,.where it is The materials mayioe mixed materials contain or fibers of other materials such as cotton, silk,

wool or regenerated cellulose and in this way differential dyelngs may be obtained where the dyes used have no aflinity for the other textile materials present. Especially valuable dfieren= tal dyeings or cross-dyed effects may be obtained on fabrcs containing mixed cellulose acetate and wool yarns when specially solubilized, dispersed dyes of the fSRA type are used. 'I'he cellulose acetate flbersmay be dyed fairly heavy shades while the wool fibers remain uncolored and un--' stained. If desired, the wool fibers may later be dyed with dyestuifs which have aflinity for the wool or the wool may be left uncolored.

As an aid in describing our invention, the same will be described with reference to the accompanying drawing wherein there is shown a paddin g device, which also constitutes part of our invention. The device, as shown, comprises a:

dye trough l containing the dye liquor 2, the dye trough being provided with a freely rotatable roller 51- mounted therein, the roller being adapted to act as a fabric guide. Positioned near the dye trough l is a padding mangle comprising a pludesired to maintain the fabric in the dye bath for longer periods of time the bath may be made lon and relatively shallow and the submerged fabric run through the bath-at any desired speed. In this way the fabric may be kept immersed for any desired period.

In order further to illustrate our invention but without being limited thereto, the following examples are given:

Example! A dye bathhaving the following composition is made up:

Parts by weight Celliton Fast Blue AF (1-methylamino-4- isopropyl amino-2-carboxyamide anthraquinone) 31.0 SRA Red VIII (p-nitroaniline-azo-dioxy-' ethyl-m-toluidine 2.5 SRA Orange BL (2-chlor-4-nitro-6-bromv I .benzene azo-dioxyethyl-m-chlor aniline) 2.0 Ethyl alcohol 6300 Water; 2000 A cellulose acetate fabric of a satin weave is passed into a dye bath or trough containing the above dye liquor and beneath a roller submerged therein, as heretofore described, the dye liquor being maintained at a temperature of 20 to 25 C. and at a-suitable level. The fabric is passed continuously through the dye bath, at the rate of 10 yards per minute, the arrangement being again for 10 minutes cellulose acetate passed through 'the'top to be dyed with a sure such that the fabric is immersed in the dye liquor for6 seconds. The fabric laden with dye liquor is then passed over an expander bar, through the lower nip of a padding mangle, over a second expander bar and finally through the upper nip of the padding mangle. The nip of the rolls is so adjusted that the weight of the dye ding mangle the fabric is passed into .a drying chamber in which air heated to 95 C. is circulated. After being dried, the fabric is scoured, tentered and calendered. The fabric thus dyed is a deep clear blue. The entire operation may be carried out in a matter of 30 to :60 minutes,

fabric retains 65% of its own whereas the usualidyeing process required from 4 to 8 hours for the same results on an equivalent I quantity of fabric.

Example 11 A mixed cellulose acetate and wool fabric containing 80% of cellulose acetate and liquor. From'the nip of pad- 20% of wool is dyed by passing it through a dye liquor having the same composition as the dye liquor inExample I. The fabric is maintained in the dye bath for 6 seconds and the fabric laden with the dye liquor is then passed between the double nip of the padding mangle. The rollsare so spaced that about 70% on liquor is retained by the fabric. The fabric from thepadding mangle is passed to a drying chamber in which air heated to about 95 C. is circulated. After being dried,the fabric'is washed for 10 minutes at 20 C. in a solutioncontaining grams per liter of a suitable'fatty alcohol sulfate detergent such as Gardinol W and then rinsed in cold water. The fabric is then washed at 60 C. with additional detergent solution of the same composition. The scouring or washing is carried out to remove excess dyestufi before the dyeing of the wool is undertaken. The undyed wool of the mixed material remains clean and unstained while the fibers are dyed a deep blue.

Example III A dye liquor having the following composition is prepared:

Cellulose acetate staple fiber in the form of a loose top is entered is at a temperature of 20 to 25 C. and'the top the bath in such a manner that it remains immersed therein for 2 minutes. On leaving the dye bath the top is run through the rolls of the padding mangle at about yards per minute and 60% of dye liquor is permitted to remain in the top as it enters the drying chamber in which air heated to 95 C. is circu trough or dye bath containing the above liquor. and beneath a roller, as heretofore .described, the dye liquor beingmaintained at a temperature of level; The dyeing of the fabric is carried out in a manner analogous It is to be understood that the foregoing detailed description is given merely by way of illustration' and that many variations may be made therein without departing from thespirit of our invention.

the weight of the fabric of dye- Having described our inventicn,'what we desire to secure by Letters Patent is:

1. Method for the coloration of an organic derivative. of cellulose textile material which comprises padding such a textile material with an aqueous alcoholic solution of a. dyestufi, said aqueous alcoholic solution comprising at least 70%, byweight, of a lower aliphatic alcohol which is a solvent for the dye, and then rapidly drying said material at an elevated temperature; 5 I 2, Method for the coloration of a cellulose acetate textile material which such cellulose acetate textile material with an aqueous alcoholic solution of a dyestufl; 1 said acetate textile material which comprises padding, such cellulose acetate textlle ma'terial'with an aqueous .70 by weight, of

. w Parts by weight SRA Orange BL 290 SRA Golden Yellow XI (dinitroaminodiphenylamine) 1,125 Celliton FastBlue AF 3,000 Ethyl alcohol 240,000 Water" 80,000

into this dyeliquor which prises ,padding lated. After drying, the top' is rinsed to'remove Y any surface color and alcoholic odor and is again dried, the whole dyeing operati n taking place in 15 to 30 minutes. Not onlyoes the dyeing the top a surprisingly increased wet strength:

drying said material -4. Method for the coloration of a fabric consolution comprising at aqueous alcoholic solution comprising at least by weight, of a lower aliphatic alcohol which. is a vsolvent for the dye, and then rapidly drying said material at an elevated temperature.

3. Method for the coloration of a cellulose aqueous alcoholic solution of a dyestuff, said alcoholic solutioncomprising 70%, by weight. of ethyl alcohol and then'r'apidly at an elevated temperature.

taining yarns of'anorganic derivative of cellulose which comprises padding;

aqueous alcoholic .solutionfcomprising at least alower aliphatic alcohol which is asolvent for the dy and then rapidly said fabric at an elevated'temperature 5. Method for the taining yarns holic solution of a dyestufi,

the dye, and then rapidlydrying said fabric at an elevated temperature.

- 6; Method for the coloration 'of a fabric conalcoholand 25%, by weight, of water, and then rapidly drying said fabric at anv elevated temperature.

7; Method for the coloration of organic derivative 'of cellulose filaments associated together in ,75 the form of a top A cellulose acetate fabric is passdin a to 25 C. and at a suitable" to Example I and thcfabric is thus dyed a navy blue.

comprises padding at least the fabric .with an; aqueous alcoholic solution of a -dyestufi, said coloration of afabric conof cellulose acetate which com- 'i. the fabric with an aqueousalcosaid aqueous alcoholic least 70%, by weight, of alower aliphatic alcohol which is a solvent for yams of cellulose acetatewhich comprises padding the fabric with anaqueous alco holic solution of a dyestufi, said aqueous alco- 'holic solution comprisingbyiweight; of ethyl V which comprises padding such rapidly drying said top at an elevated temperature. l

8, Method for the coloration of cellulose acetate filaments associated together in the form of a top which comprises padding said cellulose acetate top with an aqueous alcoholic solution 10 of a dyestufi', said aqueous alcoholic solution com-e prising at least 70%, by weight, 01' a lower aliphatic alcohol which is a solvent for the dye, and then rapidly drying said top at an elevated temperature.

9. Method for the coloration of cellulose acetate filaments associatedtogether in the form of a top which comprises paddinng said cellulose acetate top with an aqueous alcoholic solution of a dyestufi', said aqueous alcoholic solution comprising at least 70%, by weight, of ethyl alcohol, and then rapidly drying said top at an elevated temperature.

. 10. Method for the coloration of cellulose ace- I tate filaments associated together in the formoof a top which comprises padding said cellulose acetate top with an aqueous alcoholic solution of a dyestufl, said aqueous alcoholic solution comprising 75%, by weight, of ethyl alcohol and 25%,

by weight, of water, and then rapidly drying said 11. Method for the coloration of organic derivative of cellulose fibers in a'textile material containing fibers of an organic derivative of cellulose and other fibers, which comprises padding said textile material with anaqueuos alcoholic solution of a dyestufi, said aqueous alcoholic" solution comprising at least a loweraliphatic alcohol which is the dye, and then rapidly drying at an elevated temperature. v

12. Method for the coloration of the organic by weight, of

derivative of cellulose fibers in a. textile mate rial containing fibers of an organic derivative of cellulose and animal fibers which comprises padding said textile material with an aqueous alcoholic solution of a dyestuil, said aqueous a1- coholic' solution comprising at least 70%, by

-weight, of a lower aliphaticalcohol which is a.

solvent for the dye, and then rapidly drying said material at an elevated temperature.

13. Method for the coloration'of the cellulose acetate'in a textile material containing fibers of cellulose acetate and wool fibers which comprises padding said textile material with an aqueous alcoholic solution of a dyestufi, said aqueous alcoholic solution comprising at least 70%, by weight, of a lower aliphatic alcohol which is a solvent for the dye, and then rapidly drying said material at an elevated temperature.

14. Method for the coloration of the cellulose acetate in a textile material containing fibers of cellulose acetate and wool fibers which comprises padding said textile materlal with an aqueous alcoholic solution 01' a dyestufl, said aqueous alcoholic solution comprising %,by weight, of ethyl alcohol and 25%, by weight, of water, and then rapidly drying said aterial at an elevated 7 temperature.

CYRlL M. CROFI. WALTER H. HINDLE.

a solvent for 7 said material 

